Audio system messages in environments such as an automobile may be affected by both system components and external factors. The system components include, for example, sounds from the auto's radio or noise carried into the auto when the windows are open. The external factors include, for example, the noise caused when a baby is crying in the back seat or a freight train is passing in front of the car. While the system can possibly adjust the system components (such as by turning off the radio or closing the windows), it may be an annoyance to the end user. In addition, the external factors cannot be controlled by the system and may affect the Speech Intelligibility (SI) of the voice system.
Currently, systems attempt to make spoken information clearer by taking actions such as temporarily muting the radio or automatically adjusting the volume of a car radio depending on the level of engine noise. Such actions, however, are typically not sufficient to control external factors. They can also change the state of the system in ways the user may not want. Moreover, conventional techniques intended to make spoken information clearer generally do not take advantage of information provided by microphones typically found in voice systems. In addition, speaker placement is not fixed for some voice systems (such as an automated house) so delivery of the message cannot be guaranteed. For users to adopt voice systems critical information should be delivered with certainty. However, an overall solution has not been developed to solve the above problems.